Protein kinases are widely implicated in human disease, especially in cancer, and play a fundamental role in human biology. In order to understand the so-called "phospho-proteome" one needs new tools to address which particular kinase(s) are active (usually phosphorylated) in a given signal transduction network. Almost all current protein-array technologies for identifying drug-induced expression levels and phosphorylation states of specific kinases utilize antibody based capture methods. However antibody capture agents are expensive, often not scalable, and recent reports strongly suggest that fewer than 30% of available antibodies can be utilized in microarray technologies. In order to provide a viable alternative to antibodies, this proposal seeks to systematically develop a new class of bivalent capture agents (BCAs) for kinases that link high-affinity small molecules to phage-displayed peptides. BCAs have the potential to be specific, scalable, and economical to produce. These salient features makes our BCAs attractive as a new class of reagents for use in array technology for understanding the regulation of kinase phosphorylation, which plays a central role in numerous signaling networks that are perturbed in human diseases, especially cancer. PUBLIC HEALTH RELEVANCE: Protein-kinases lay at the heart of signal transduction cascades, which when perturbed lead to human diseases such as cancer. Thus, the identification of new classes of bivalent reagents for capturing kinases in microarray applications has direct utility in understanding the pathophysiology of human diseases and aid in the development of novel diagnostics and therapeutics.